Production of artificial textile materials



March 9, 1937. w. I. TAYLOR 2,072,927

I RODUCTION OF ARTIFICIAL TEXTILE MATERIALS Filed March 15, 1933 Flql- WILLIAM I TAYLOR \NVENTOR Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE PRODUCTION OF ARTIFICIAL TEXTILE MATERIALS Application March 15, 1933, Serial No. 660,824 In Great Britain April '1, 1932 7 Claims.

This invention relates to the production of artificial textile materials in which a number of primary artificial filaments are caused, while in a sticky or tacky condition, to merge and coalesce together to form a unitary product of heavy flattened cross-section.

A method of producing products of the kind referred to above is described in U. S. application S. No. 406,356 filed 11th November, 1929 according to which a plurality of artificial filaments in the form of long continuous lengths are rendered sticky or tacky by the application of a controlled amount of a material which has a solvent, restricted solvent or softening action on the sub- 15 stance of the filaments, and the filaments while in a condition to adhere to each other are then submitted to the action of pressure e. g. by passing them between one of more pairs of positively driven pressure rollers, and are then allowed to harden to form a single filament or strip of flattened cross-section. Pressure may be applied to the whole length of the filaments to produce a ribbon, tape or straw-like product, or it may be applied intermittently to produce a product havin alternating lengths of flattened and rounded cross-section, or again the pressure may be varied to give a flattened product of varying widths alternating if desired, with lengths of rounded cross-section.

According to U. S. application S. No. 569,250 filed 16th October, 1931 which describes an improvement in or modification of the invention described in U. S. application S. No. 406,356 filed 11th November, 1929 referred to above, the fila- 35 ments while in a condition to adhere to each other are caused to pass under tension over a curved surface in such a manner that the filaments unite and coalesce together to form a single strip of straw-like cross-section. The pressure 40 between the curved surface and the sticky filaments causes the filaments to pass over the surface in the form of a flattened thread, and to unite together to form a flattened product. The filaments may be passed round one or more of such surfaces, making any convenient arc of contact therewith, according to the degree of flatness required in the final product.

It has now been found that instead of bringing the filaments into a sticky condition and then applying pressure to them so that they adhere to one another and are caused to form a flattened unitary product, the filaments may first be brought into the form of a flattened thread of individual filaments and a solvent may be ap- 55 plied subsequently thereto, so that provided that the disposition of the filaments in flattened form is maintained during the application of the solvent, the filaments adhere to one another in that form without the application of pressure to assist such adhesion and to bring them into that form. According to the present invention therefore, a plurality of filaments in the form of long continuous lengths are associated together in the desired form of a flattened thread of individual filaments and a solvent, restricted solvent or softening agent is then applied thereto by means of an applying surface adapted to maintain the filaments in the desired form, so as to cause them to unite together to form a single strip or ribbon of flattened or straw-like cross-section. As in U. S. applica tion S. No. 569,250 filed 16th October, 1931 the filaments are associated as a flattened thread, but in the present case adhesion of the filaments does not occur until after the filaments have been so brought together, so that the use of pressure to bring the filaments together in flattened form and. cause them to unite together, is unnecessary.

The invention is particularly applicable to the.

treatment of artificial filaments having a basis of cellulose acetate or other cellulose derivatives, whether produced by the dry or evaporative method, or by the wet or coagulation method. Examples of other cellulose derivatives which may form the basis of the filaments are cellulose esters, e. g. cellulose formate, propionate or butyrate, and nitrocellulose; cellulose ethers, e. g. methyl, ethyl and benzyl cellulose; and the condensation products of cellulose and glycols orother polyhydric alcohols. By the employment of suitable solvent or softening agents, other types of artificial filaments, e. g. viscose and cuprammonium artificial filaments, may likewise be treated, suitable solvents for regenerated cellulose filaments of this type being zinc chloride solution or Schweitzers reagent. Furthermore, the filaments may be elementary filaments, employed in the form in which they are first produced, or they may be unitary filaments of rounded or other cross-section, formed by the coalescence of a number of elementary filaments. The filaments may be formed into a flattened unitary product continuously with their production by the dry or evaporative method, or by the wet or coagulation method, and while they are proceeding to a winding or twisting and winding or other collector device, or they may be treated during a bobbin-to-bobbin or other winding or twisting and winding operation.

Solvents suitable for use with filaments of cellulose acetate or other organic derivative of cel-- lulose are low boiling solvents such as acetone (commercially pure or mixed with water) ethylene dichloride and ethyl or methyl alcohol, dichlorethylene and ethyl or methyl alcohol, and the like, medium or high boiling solvents or plas-' tifiers such as diacetin, triacetin, ethyl lactate, diacetone alcohol (alone or mixed with water or alcohol) dibutyl tartrate or tricresyl phosphate, and mixtures thereof. The use of high boiling solvents or plastifiers imparts increased pliability to the product. When a volatile solvent such as acetone is used, means may be employed to assist its evaporation for the product after coalescence, and if desired such means may be associated with an apparatus for the recovery of the solvent. Such solvents or softeners as are not removed by evaporation may if necessary be removed by any other suitable operation, such as washing, or may be allowed to stay in the products.

'The solvent, restricted solvent or softening material may be applied in any convenient manner and by any suitable means which provide a solvent applying surface adapted to maintain the thread of filaments in the desired formation of a flattened thread. Thus for example, the thread of filaments may be passed over Wicks, rods or rollers dipping into or otherwise supplied with the material to be applied to the filaments, the surface of such applying means over which the filaments pass being so disposed as to maintain them in their flattened state. Or again the filaments may be passed between two such applying surfaces, it being unnecessary that any substantial pressure should be applied between the surfaces in order to flatten and coalesce the filaments, which, according to the present invention will adhere to one another without the application of such pressure. Thus the moistening device described in U. S. application S. No. 538,484 filed 19th May, 1931 is very convenient for this purpose. After the application of solvent, the filaments adhere to each other in the form in which they have been disposed, and form a unitary product of flattened cross-section.

The solvent applying means in addition to being adapted to maintain the filaments in the form of a flattened thread, may be such as to apply an adjustable amount of solvent to the filaments, in order that a relatively large or small quantity of solvent may be applied regardless of the speed at which the filaments are travelling. Thus, by applying a relatively small amount of solvent to the filaments, e. g. just enough to render the filaments sticky or tacky the final product may be caused to-retain in its structure to some degree, the fibrous qualities of the individual filaments of which it is composed, so that a product of great strength and flexibility results. Or alternatively if a more homogeneous product is desired, a sulficient quantity of solvent may be applied to cause the filaments to merge and coalesce thoroughly into one another, so that the fibrous nature of the individual filaments is destroyed.

The flattened product may be collected in any suitable manner, preferably by simple winding on to a bobbin without twisting, or by hanking. If necessary, stickiness due to residual solvent or softening material may be removed by treating the finished product with suitable lubricant, e. g. from a wick, which maybe of the same form as that by means of which the solvent was applied.

The filaments may be brought into the form of a flattened thread prior to the application of solvent or softening material in any convenient manner. Thus they may be passed round curved surfaces of relatively small diameter such as rods. bars or the like as described with reference to filaments already softened in U. S. application S. No. 569,250 filed 16th October, 1931, the solvent material in the present invention however, being applied after their formation into a flattened thread. Or again, the filaments may be brought into the form of a flattened thread by passing them through a reed adapted to separate them and to hold them in the desired form. After passing them through a reed in the manner described above, the flattened bundle of filaments may, if desired, be twisted slightly to reduce the width and to increase the thickness of the flattened thread. This may be done for example by passing the filaments after they have left the reed round a rod or bar set at an angle to the width of the thread of filaments leaving the reed.

The operation of causing the filaments to adhere to one another and of maintaining them before adhesion in the form of a flattened thread may be assisted by maintaining the threads under tension during the whole or a part of the operation. For this purpose the filaments may be passed through a suitable tension device e. g. a gate tension device, being collected under tension after the formation of the unitary flattened product. Such a tension device may be adapted to bring the filaments initially into the flattened form, the device thus performing a double function. Instead of passing the filaments through a gate tension device or instead of collecting them under tension or both, the flattened thread of filaments or the flattened unitary product or both may be maintained under tension by means of tension rollers. In this case however, it is undesirable that the filaments should pass round such tension roller in the usual manner and it is preferred that the necessary are of contact between the filaments and the rollers should be maintained by means of nipping rollers or jockey rollers. If however, tension is applied to the filaments before they are formed into a flattened thread of filaments, this may be done by passing the thread before flattening round the tension roller in the usual manner.

Effects of an ornamental nature may be produced in the product by means of the incorporation of effect materials, or by other methods as described in U. S. application S. No. 569,250 filed 16th October, 1931. The ribbons, tapes or strawlike products manufactured according to the present invention may be Woven or otherwise formed into fabrics or articles, and are capable of a wide use, for example, in millinery and as insulation for electrical purposes.

The invention will now be described in greater detail with reference to the accompanying drawing but it is to be understood that this description is given by way of example only and is in no way limitative.

Figure 1 is a side elevation of an apparatus for carrying out the invention and Figure 2 is a part sectional elevation of a detail of Figure 1.

Referring to Figure 1 a number of threads 3 are drawn from bobbins 4, through guides 5 disposed on the axes of the bobbins. The several threads 3 are passed through a number of closely spaced pigtail guides 6 mounted on a bar I, so that they are collected in the form of a broad flat ribbon 8. The filaments then pass in zig-zag fashion between two vertical rods 9 which cause the filaments to form a compact ribbon IO- lying filaments.

in a vertical plane. The ribbon ID of independent filaments is then passed through a solvent applying device H which is shown in greater detail in Figure 2. The solvent is applied from the surfaces of wicks l2 which surfaces maintain the ribbon It! in its flattened condition during the application of the solvent. The solvent causes the threads to become sticky, with the result that they adhere to one another to form a unitary product l3 which cross-section is the same as that of ribbon I!) of independent filaments entering the applying device.

The unitary ribbon i3 is then passed through a drying chamber l4 provided with steam heating pipes I5 to vaporize the solvent material therein, steam being provided to the pipes by means of an inlet 5 and an outlet l1. Air is drawn from the chamber l4 by means of a draw-off pipe IS, the air passing in the opposite direction to the The air drawn off in this manner carries away the solvent vapours, and may be passed to a solvent recovery plant. The ribbon l3 leaving the chamber l4 passes to the guide l9 and a reeling device 20 by means of which the ribbon is collected without twisting. The reeling device 20 provides the power required to draw the filaments along their path, overcoming the tension imparted by the rods 9, which bring the filaments into the form of a flattened thread.

The device His shown in detail in Figure 2, and is an elaboration of the liquid applying device described in U. S. application S. No. 538,484 filed 19th May, 1931. The two wicks l2 dipping into a vessel 2! of solvent or softening liquid are 7 carried at the upper ends of a pair of crossed levers 22, the lower ends of the levers being provided with weights 23 which cause the wicks 12 to press lightly against one another. The filaments pass between the Wicks in the form of a ribbon l0 and the wicks, while applying solvent or softening liquid thereto, maintain the filaments in their flattened condition.

In order to adjust the amount of solvent or softening material applied to the ribbon III, the

. level of solvent liquid in the vessel 2| is adjustable. For this purpose a pipe 25 is provided connected by means of flexible tubing to the vessel 2| and attached to the side of the vessel by means of an adjustable clip 21. The mouth 28 of the pipe 25 is maintained at the level required of the liquid within the vessel 2| and serves both as a means of replenishing the liquid in the vessel 2i and a means for observing the height of liquid. The level of the liquid in the vessel 2| can be adjusted by raising or lowering the tube 25 and the clip 21. By adjusting the level of the liquid in the vessel 2! the amount of liquid applied to the ribbon II] may also be adjusted. A cover 29 is provided over the vessel 2| in order to prevent undue loss by evaporation of the solvent material.

What I claim and desire to secure by Letters Patent is:- I

1. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of long continuous filaments in the form of a flattened thread of individual filaments and causing said flattened thread to pass in contact with a surface adapted to apply thereto a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread, thereby causing the softened filaments to unite together to form a single ribbon of flattened cross-section.

2. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of continuous artificial filaments of an organic derivative of cellulose in the form of a flattened thread of individual filaments and causing said flattened thread to pass in contact with a surface adapted to apply thereto a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread, thereby causing the softened filaments to unite together to form a single ribbon of flattened cross section.

3. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of continuous artificial filaments of cellulose acetate in the form of a flattened thread of individual filaments and causing said flattened thread to pass in contact with a surface adapted to apply thereto a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread, thereby causing the softened filaments to unite together to form a single ribbon of flattened cross section.

4. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of long continuous filaments in the form of a flattened thread of individual filaments and causing said flattened thread to pass between two surfaces adapted to apply thereto a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread, thereby causing the softened filaments to unite together to form a single ribbon of flattened cross-section.

5. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of long continuous filaments in the form of a flattened thread of individual filaments and causing said flattened thread to pass in contact with a surface adapted to apply thereto by capillary action a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread, thereby causing the softened filaments to unite together to form a single ribbon of flattened cross-section.

6. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of long continuous filaments in the form of a flattened thread of individual filaments and causing said flattened thread to pass between two surfaces pressing lightly together and adapted to apply thereto by capillary action a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread so as to cause them to unite together to form a single ribbon of flattened cross-section.

7. Process for the production of unitary products of heavy and flattened cross-section, said process comprising associating a plurality of long continuous filaments in the form of a thread, passing said thread in contact with a surface adapted to impart tension thereto by friction and to bring the thread into the form of a flattened thread, and passing said flattened thread in contact with a surface adapted to apply thereto a liquid having a softening action upon the filaments and to maintain the filaments in the form of a flattened thread so as to cause them to unite together to form a single ribbon of flattened cross-section.

. WILLIAM IVAN TAYLOR. 

